Continuous switching device for the gear mechanism of an electric wrist watch

ABSTRACT

A continuous switching or incremental advancing device for the gear mechanism of an electric wrist watch having a preferably electromagnetically driven balance and a switch armature driven by the balance. The switching device is provided with a long input arm and a short output arm and with a ratchet wheel driven by the switch armature.

United States Patent Scholz [451 Aug. 22, 1972 [54] CONTINUOUS SWITCHING DEVICE FOR THE GEAR MECHANISM OF AN ELECTRIC WRIST WATCH [72] lnventor: Gunther Scholz, Schramberg, Germany [73] Assignee: Firma Gebruder lvnghans G.m.b.H.,

Schramberg, Germany I22] Filed; July l5, l97l 21 Appl. No; 162,932

Related US. Application Data [63] Continuation-impart of Ser. No. 875,646, Nov.

12, 1969, Pat. No. 3,611,707.

[52] US. Cl. ..58/28 D, 58/116 [51] Int. Cl. ..G04c 3/04 [58] Field of Search ..58/28 R, 28 D, 116 R, 117;

[56] References Cited 7 UNITED STATES PATENTS 3,059,500 10/1962 Schneiter ..58/28 3,462,942 8/1969 Meitinger et al. ..58/28 3,488,942 l/l970 Hougendobler ..58/28 2,954,662 l0/l960 Detwiler ..58/28 D FOREIGN PATENTS OR APPLlCATlONS 504,694 4/1939 Great Britain ..58/28 D Primary Examiner-Richard B. Wilkinson Assistant Examiner--Edith C. S. Jackmon Attorney-Burns, Doane, Swecker & Mathis 5 7 ABSTRACT A continuous switching or incremental advancing device for the gear mechanism of an electric wrist watch having a preferably electromagnetically driven balance and a switch armature driven by the balance. The switching device is provided with a long input arm and a short output arm and with a ratchetwheel driven by the switch armature.

3 Claims, 2 Drawing Figures llllllllll] CONTINUOUS SWITCHING DEVICE FOR THE GEAR MECHANISM OF AN ELECTRIC WRIST WATCH RELATED APPLICATION This application is a continuation-in-part of my prior, pending application Ser. No. 875,646, now U.S. Pat. No.3,611,707 filed Nov. 12, 1969, and entitled Continuous Switching Device for Advancing the Wheel Mechanism of an Electric Clock.

GENERAL BACKGROUND, OBJECTS, AND

SUMMARY OF THE INVENTION A In the case of watches with a drive rate regulating oscillator, where the drive of the gear mechanism mechanically results from the rate regulating oscillator and where, for example, the rate regulating oscillator is driven electromagnetically via an electronic circuit, the development of the continuous switching device is of particular importance. Any additional loading of the oscillator mechanism should be avoided as much as possible and thus the continuous switching device must have as high a degree of effectiveness as possible.

A continuous switching device already has become known, through U.S. Pat. No. 3,488,942. In this case, an armature fork is used with arms of different lengths and of such size that the ratchet wheel driving the mechanism of the hands is encircled by one of the arms. Thus, these arms, in the case of movement of the switch fork or pallet will come into contact with the ratchet or index wheel alternately on diametrically opposed points of this ratchet wheel. This known continuous switching device appears to operate with very small power losses. However, it has a great requirement for space and therefore is not suitable for small watches, especially wrist watches.

The object of the invention is to create a continuous switching arrangement with both a small power loss characteristic and a small space requirement, which is suitable for wrist watches and which operates with a particularly high degree of effectiveness.

Through this invention it has been discovered, that this is possible whenever the opening or aperture angle of the armature a amounts to 90 to 120, whenever the distance between the axis of the switch armature or fork and the axis of the ratchet wheel is at least 0.8 and at most equal to the diameter of the ratchet wheel, and whenever the ratio of the lengths of input arm and output arm of the armatures lies between 1.3 and 1.7. Surprisingly, comparatively speaking, a very high degree of effectiveness will result from a continuous switching device developed in this compact way.

DRAWINGS The invention is to be explained in more detail in the succeeding paragraphs in an embodiment given by way of example in the drawing. In the drawings:

FIG. 1 shows a top plan view of an embodiment of the continuous switching device according to the invention;

FIG. 2 is another top view of the continuous switching device according to F IG. 1, however, with a different position of the switch armature shown; and

FIG. 3 shows a side view of the continuous switching device according to FIG. 2.

DETAILED DESCRIPTION PREFERRED EMBODIMENT AND SCOPE In the Figures, reference number 10 designates a part of a mounting plate of the mechanism of the wrist watch. Reference number 11 is a switch armature or fork of the watch mechanism and is pivotally supported by an axle l2. Axle 12, in essence, pivotally supports armature 11 relative to plate 10.

Arm of switch armature 11 has been developed as a fork. Fork 1 1c is engaged and oscillated by a switch or roller pin of a balance, which is well known and has not been shown. As a result of this coaction, the swiveling movement of the fork l 1 will be effected. The drive of balance can be accomplished in a known manner, in a noncontacting manner, by way of electromagnets via an electronic circuit, preferably a transistor circuit.

Armature fork 11 has been provided with two arms 1 la and 11b, of which input arm 1 lb is longer than output arm 11a. The ratio of length L; of input arm 11b to length L of output arm 11a amounts to about 1.6, in the case of the embodiment shown by way of example. Through this invention it has been found that the ratio may be between 1.3 and 1.7 without considerably impairing the high degree of effectiveness.

Arms 11a and 11b, on their ends, carry palettes or pawls l6 and 17 which can be either ceramic or stones or can consist of steel. Naturally, it also is possible to use peg type palettes instead of the palettes shown in the drawing. The illustrated palettes are inserted longitudinally of the plane common to the arms and fork of the switch armature and into the arms of said switch armature. The transverse median plates of the palettes extend perpendicular to the plane of the armature switch. Instead of the peg palettes, round pegs made of ceramic, stone or steel also can be provided.

The slewing or oscillating motion of the switch fork or armature 11 is limited by two stop pegs 13 and 14. These stop means possibly also could be developed as magnetic pegs" in order to hold the armature fork in its terminal positions. In the case of the embodiment shown by way of example, however, nonmagnetic pegs 13 and 14 have been provided.

For holding the switch fork in its terminal positions, i.e. extremities of normal oscillating movement, a permanent magnet 15 has been provided. This magnet 15 cooperates with switch fork 11, which itself consists of ferromagnetic material. In order to achieve a holding force in the terminal positions, a perforation 11d has been provided in switch fork l 1.

The palettes 16 and 17 cooperate, in a known manner, with teeth 18a of ratchet wheel 18, which is supported on axle 20.

The distance between the axis of axle 112 of switch fork 11 and the axis of axle 20 of ratchet wheel 18 amounts, in the embodiment shown by way of example, to about 0.9 times the diameter D of ratchet wheel 18. This distance a can vary somewhat from this value without this having any substantial adverse influence on the degree of effectiveness of the continuous switching device. According to the invention, the value of distance a may be between 0.8 times the diameter D of ratchet wheel 18 and the simple diameter D of ratchet wheel 18 to achieve the compactness required in a wrist watch.

Significantly, any plane extending from the extremity of pawl 17 of input arm 11b to the extremity of pawl 16 of output arm 11a will lie between the pivot axes of ratchet wheel 18 and switch armature 11, as defined by pivot means 20 and 12. This feature enables the mechanism to be compact and not interfere with other components on the side of wheel 18 remote from armature ll.

On axle 20 of ratchet wheel 18 there is attached additionally a cog or ratchet wheel 19, which cooperates with click spring 21 or ratchet type holding device. Preferably, click spring 21 at its free end carries a stone or pawl 22 which engages with the toothing of cog or ratchet wheel 19.

The click spring has been provided with a beht lobe 21a which has an aperture 21b. A cam 24 engages with this aperture 21b, which cam is attached rotatably in a plate of the watch mechanism. In this manner the position of stone 22 is adjustable in regard to cog wheel 19. Furthermore, an additional cam 23 has been provided which likewise has been attached rotatably in a plate of the watch mechanism. The initial stress of click spring 21 can be adjusted with the aid of this cam 23.

Instead of click spring 21 shown, a pawl of a known type, developed as a double ratchet, can be used, which engages directly with teeth 18a of the ratchet wheel 18. In this connection, any suitable device operable to prevent movement of wheel 18, other than that effected by armature 11, will suffice.

According to the invention, the armature aperture angle a also is of importance, and is to lie between 90 and 120 if the desired high degree of effectiveness is to be achieved. This angle is that defined by lines extending from the axis of pivot means 20 to the points where the drive surfaces of pawls l6 and 17 intersect a circle extending coextensive with the outer edges of the driven surfaces of teeth 18a.

In a sense this armature angle can be viewed as the angle defined by lines extending from the axis of rotation of ratchet wheel 18 to points on the periphery of a circle, which circle is coextensive with the radially outermost extremities of the portions of teeth 18(a) which are drivenly engaged by pawls l6 and 17, and which points are defined by the intersection of this circle by corresponding points on the drive portions of these pawls which engage teeth 18a.

Investigations have shown that the continuous switching arrangement according to the invention can be produced with small dimensions, so that it can be used in the case of wrist watches, whereby the degree of effectiveness is considerably better than that of known continuous switching devices for wrist watches.

Those familiar with this disclosure may envision additions, substitutions, deletions or other modifications which would fall within the scope and purview of the invention as set forth in the appended claims.

What is claimed is:

1. An improvement in a continuous switching arrangement for the drive mechanism of an electric wrist watch, said watch having an electromagnetically driven balance, and said switching arrangement comprising:

a switch armature operable to be driven by said balance;

said switch arm including a relatively long input arm and a relatively short output arm; and

a ratchet wheel driven by the switch armature; said improvement comprising said switching arrangement having an armature aperture angle of between about and about said switching arrangement having a distance between the pivot axis of the switching armature and the pivot axis of the ratchet wheel of at least about 0.8 times the diameter of the ratchet wheel and not exceeding said diameter;

a ratio of lengths of said input arm to output arm being between about 1.3 and about 1.7.

2. An improvement as described in claim 1 wherein the extremities of said input and output arms are operable to be aligned with a plane disposed between said pivot axis of said switch armature and said pivot axis of said ratchet wheel.

3. An improvement in a continuous switching arrangement for the drive mechanism of a wrist watch, said watch having a driven balance, and said switching arrangement comprising:

a switch armature operable to be driven by said balance;

said switch arm including a relatively long input arm and a relatively short output arm; and

a ratchet wheel driven by the switch armature; said improvement comprising said switching arrangement having an armature aperture angle of at least about 90;

said switching arrangement having a distance between the pivot axis of the switching armature and the pivot axis of the ratchet wheel of at least about 0.8 times and diameter of the ratchet wheel;

a ratio of lengths of said input arm to output arm being at least about 1.3 and;

the extremities of said input and output arms being operable to be aligned with a plane disposed between said pivot axis of said switch armature and said pivot axis of said ratchet wheel.

32 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3. 685. 279 Dated Au ust 22. 1972 Inventor(s) Gunther Scholz It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the caption [73] Assigneez", correct Firma Gebruder Ivnghans G. m. b. H. to read Firrna Gebruder Junghans G.rn. b. H

Signed and sealed this 13th day of February 1973.,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 33 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3.685.279 v Dated Au ust 22. 1972 Inventor(s) Gunther Scholz It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the caption [73] Assigneez", correct Firms Gebruder Ivnghans G.rn. b. H. to read Firma Gebruder Junghans (5.111. b. H

Signed and sealed this 13th day of February 1973.,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. An improvement in a continuous switching arrangement for the drive mechanism of an electric wrist watch, said watch having an electromagnetically driven balance, and said switching arrangement comprising: a switch armature operable to be driven by said balance; said switch arm including a relatively long input arm and a relatively short output arm; and a ratchet wheel driven by the switch armature; said improvement comprising said switching arrangement having an armature aperture angle of between about 90* and about 120* ; said switching arrangement having a distance between the pivot axis of the switching armature and the pivot axis of the ratchet wheel of at least about 0.8 times the diameter of the ratchet wheel and not exceeding said diameter; a ratio of lengths of said input arm to output arm being between about 1.3 and about 1.7.
 2. An improvement as described in claim 1 wherein the extremities of said input and output arms are operable to be aligned with a plane disposed between said pivot axis of said switch armature and said pivot axis of said ratchet wheel.
 3. An improvement in a continuous switching arrangement for the drive mechanism of a wrist watch, said watch having a driven balance, and said switching arrangement comprising: a switch armature operable to be driven by said balance; said switch arm including a relatively long input arm and a relatively short output arm; and a ratchet wheel driven by the switch armature; said improvement comprising said switching arrangement having an armature aperture angle of at least about 90* ; said switching arrangement having a distance between the pivot axis of the switching armature and the pivot axis of the ratchet wheel of at least about 0.8 times the diameter of the ratchet wheel; a ratio of lengths of said input arm to output arm being at least about 1.3 and; the extremities of said input and output arms being operable to be aligned with a plane disposed between said pivot axis of said switch armature and said pivot axis of said ratchet wheel. 